Zebrafish Larva Orientation and Smooth Aspiration Control for Microinjection.

Objective: The zebrafish has been proven to be a significant model organism in various research fields. For investigating the in vivo properties of biologics within zebrafish with developed organs, an automated zebrafish larva organ injection system is crucially needed. However, current zebrafish larva manipulation techniques cannot accomplish this operation efficiently and continuously.

Methods: In this paper, we present a novel zebrafish larva manipulation technique with two key steps in the microinjection system: orienting and aspirating zebrafish larvae automatically. The orientation control is realized in a customized microfluidic chip, after which the larva moves tail-first until reaching the channel exit. Then a dynamic model of larva aspiration is established and an adaptive robust controller is designed.

Results: Experimental results demonstrate that high success rate can be reached and damage to larva body is reduced.

Conclusion: The presented strategy is capable of orienting and aspirating zebrafish larvae smoothly and efficiently.

Significance: The proposed methods have the advantage of low cost, easy implementability and good stability.